目的：以住院病患為研究對象，評估癲癇患者在同時接受valproate與carbapenem抗生素治療後，此交互作用結果對其valproate藥物血中濃度與癲癇發作頻率之影響。 
方法：本研究係以高雄長庚紀念醫院住院病患為研究對象之回溯性病例系列研究。研究資料擷取自2007年1月至2009年12月，此三年期間符合收案條件住院病患之電子病歷記錄，並以Drug Interaction Probability Scale (DIPS)評估carbapenem抗生素造成收案病例valproate藥物濃度下降之相關性。研究結果以平均值±標準差(mean±SD)及百分比(%)表示，p值小於0.05視為具統計上之顯著差異，進行描述性統計分析。
結果：本研究納入分析的病患人數有37名，經以DIPS評估藥物交互作用之相關性後，結果發現有28名患者valproate藥物濃度下降與carbapenem抗生素的使用認定為“很可能相關”(總積分5-8分者)，另有9名患者之相關性積分為4分，因此評估為“可能相關”(總積分2-4分者)。於併用carbapenem抗生素後，所有患者之valproate平均藥物濃度由63.9±18.6 mg/L顯著降低至22.8±13.8 mg/L (p< 0.001)，前後之藥物濃度差異達-41±14.8 mg/L，而於此段期間共有51% (n=19) 的病患出現急性癲癇樣發作症狀。
結論：我們回溯性分析37名患者之資料記錄，發現此交互作用會導致所有病患的valproate藥物濃度顯著地降低( p< 0.001)，對於正接受valproat治療的癲癇患者而言，同時併用carbapenem抗生素將會影響到valproate的癲癇發作控制效果，增加發作的風險，應極力避免。

OBJECTIVE: 
To evaluate a population of hospitalized patients who were simultaneously treated with valproate and carbapenem antibiotic and assessed the effect on clinical outcome.
METHODS: 
A retrospective case series study was conducted in Kaohsiung Chang Gung Memorial Hospital. Data are collected from computerized charts of patients hospitalized between January 2007 and December 2009, and these patients meet the criteria of receiving therapy with valproate and carbapenem antibiotic during hospitalization. We used the Drug Interaction Probability Scale (DIPS) to assess the probability of a causal relationship between a potential drug-drug interaction and an observed event. All results are presented as mean±SD and percentage (%). For all comparisons, a p-value of ≤0.05 will be considered statistically significant. Descriptive statistical analysis was performed.
RESULTS: 
A total of 112 patients were studied. Thirty-seven patients met the inclusion criteria. The interaction was considered to be probable in 28 patients and possible in 9 patients, as calculated by the DIPS. During concomitant therapy with carbapenem, a total of nineteen patients (51%) had acute epileptic seizures. Valproate plasma concentration significantly decreased from 63.9 ± 18.6 mg/L (mean ± SD) to 22.8 ± 13.8 mg/L ( p< 0.001) following carbapenem administration.
CONCLUSIONS: 
Our results indicate that coadministration of carbapenem antibiotic may lead to a deterioration of epileptic control in the patients who receive valproate for the treatment of epileptic seizures and should be avoided.